The utilization of testing and monitoring instrumentation devices for usage with modern aircraft is a focus of consideration. This is especially the case in light of compliance with ever-changing and increasingly stringent governmental safety regulations. Such test instrumentation devices may be necessary to perform engine vibration analysis, for example. In addition, other devices may be used to test fuel systems, hydraulic pressure systems, avionics systems, on-board communications systems, environmental control systems, and all other aircraft systems and subsystems which are electrically or electro-mechanically tested and/or monitored.
Generally, a test instrumentation system would include a test instrumentation device and an apparatus to connect the device to an output from a sensor in the aircraft. For example, in the context of engine vibration analysis, an engine vibration analysis device, via an electrical cable harness, would be connected to an accelerometer located adjacent to an aircraft engine. It is contemplated that the test instrumentation device would perform test sequences based upon a variety of variables, which could include the specific aircraft type and model, and specific type and model of the relevant aircraft component parts, such as the engines. Thus, there must be provided a method of informing the test instrumentation device of the relevant information regarding these variables.
A variety of test instrumentation system configurations have been developed to provide the system with the relevant information regarding the particular equipment configuration, such as the aircraft type and engine type configuration, to allow it to perform the appropriate test sequence. For example, a conventional test instrumentation system configuration may employ a generic test instrumentation device which mates with an aircraft/engine type configuration specific insert unit containing the test specification data corresponding to that particular aircraft/engine type configuration. In the case of a portable test instrumentation device which is used for ground-based servicing of a variety of aircraft/engine type configurations, however, the user is burdened with the requirement of purchasing a variety of aircraft/engine type specific insert units.
Another conventional system approach employs a generic test instrumentation device which has a stored library of test specifications corresponding to a variety of aircraft equipment configurations. Such a generic test instrumentation device is provided with a selection device through which the operator inputs, for example, the aircraft/engine type configuration, thereby informing the test instrumentation device which set of test specifications to use for analysis. This selection device may be a dial with various settings corresponding to a given aircraft/engine type or a key pad which a user types in a specific code corresponding to a given aircraft/engine type. This system, however, is subject to user errors in correctly setting the system to the particular aircraft/engine type because of the nature of the selection device used. For example, where the system is used to service multiple aircraft/engines on the ground, each time the user services a different aircraft/engine, the user must input through the selection device which aircraft/engine type the system is connected to. In the case of a dial type selection device, the user is required to turn the dial to the setting corresponding to the appropriate aircraft/engine type. This task is subject to user error, as the user may be inattentive while setting the dial or may simply forget to change the setting of the dial completely. In the case of a key pad type selection device, the user is required to key-in code corresponding to a given aircraft/engine type. Similarly, this task is subject to user error, as the user may be inattentive while keying-in the appropriate aircraft/engine type code or may key-in the code from memory (which of course is fallible).
Another system approach employs a configuration having an aircraft/engine type specific test instrumentation device with aircraft/engine type specific data being integral to the device. In the case of a portable test instrumentation device which is used for ground-based servicing of a variety of aircraft/engine types, the user burdened with the requirement of purchasing numerous test instrumentation devices for each aircraft/engine type. Moreover, the test instrumentation device is the most expensive system component. In addition, regardless of whether the aircraft/engine type specific test instrumentation device is integral to an aircraft/engine or portable used to service a variety of aircraft/engines, this configuration requires a manufacturer to produce a multitude of different test instrumentation devices, rather than a single generic one. Such a manufacturing requirement imposes added product costs.
As a safety measure, it is customary for aircraft manufacturers to specify that the instrumentation interface for cables connectors, wire harnesses and other electronic connection devices are constructed in a manner which helps ensure that appropriate test instrumentation devices are connected to the aircraft/engine. Thus, to ensure that the appropriate test device is connected to an aircraft/engine, the instrumentation interface may be formed such that only the appropriate mating connectors are engaged. In practice, for example, a maintenance worker is physically prevented from connecting cable attached to a given aircraft/engine type to a test instrumentation device suited for a different aircraft/engine type.
A conventional arrangement for is to provide the interface with at least one mechanical guide key configured to guide interface engagement. In addition, the guide key is disposed in the connector interface having an orientation specific to a particular type of aircraft/engine. Further, multiple guide keys may be provided having a combination of orientations corresponding to a particular type of aircraft/engines. Thus, in the case of an electrical pin connector, where various pins of a pin connector are engaged with the corresponding female connector, a guide key may be disposed in a male connector (pin-side) to guide the pins into proper alignment with the corresponding female connector. The corresponding female connector would be provided with a key engagement member which is particularly oriented to engage the guide key. Thus, this arrangement prevents the engagement between non-corresponding connectors suited for two different aircraft/engine types.
It is therefore evident that there exists a need in the art for a system of connecting test instrumentation devices to a variety of aircraft equipment configurations, such that the connection interface is formed to only allow engagement between a test instrumentation device and corresponding aircraft and the instrumentation device is provided with the identity of the equipment type configuration that it is connected to, in order to perform an appropriate test sequence.